Engine Compartment Maintenance; Air Filter Element, Replacing; Spark Plugs, Replacing - BMW 1989-1995 525i Service Manual

020-10
MAINTENANCE PROG RAM
7. Start engine and check that oil pressure warning light
immediately goes out. Allow engine to run for a few
minutes to circulate new oil. Check for leaks at drain
plug and oil filter. Stop engine and recheck oil level.
CAUTlON -
• Dispose of used oil properly. Use lighl·sealing
containers and mark Ihem clearly. Check with
the place of purchase ebout disposat.
• li the oil pressure warning light does not immedi-
alely go out aller the engine is stertea. quickly
turn Ihe engine off. Loosen the oil filter or lilter
cover slightly. Restart the engine. As soon
as
oil
begins to run out of the filter or filter cover. turn
the engine off and tighten the filter or cover. This
will release any trapped air that is blocking oil
ttow.
ENGINE COMPARTMENT MAINTENANCE
Air filter element, replacing
The specified maintenance intervals for replacing the air fil-
ter element are based on normal use. If the car is operated pri-
marily in dusty conditions. the air filter should be serviced
more frequently. A dirty air filter starves the engine for air, re-
ducing power output and increasing fuel consumption.
NOTE -
On M20 and M50 engines. the air filter housing is in the
left front corner of the engine compartmenl. On M30
and M60 engines. Ihe air filter housing is in the front
right corner of the engine compartment.
The upper and lower parts of the air filter housing are fas-
tened togethe r with spring clips around the outside edge. To
replace the air filter element and unfasten the clips as neces-
sary. Separate the upper air filter housing from the lower part
just enough to remove the filter element. See Fig. 5.
Fig . 5.
Air
filter housing In front lett (dnver 's) side of M50 engine corn-
panmeru. Unchp spring clips (arro w s) 1 0 remove air filter.
ENGINE COMPARTMENT MAINTENANCE
Take note of the installed position of the filter. Wipe clean
the inside of the air filter housing using a lint-free cloth and in-
stall the new filter. Reinstall the upper air filter housing, mak-
ing sure that the two halves are mated correctly. Refasten the
spring-clips and tighten the mounting nuts. See Fig. 6.
001 '9 19
Fig. 6. Air filler being removed from air filler hOUSing. A ir filter housing
will vary slightly between models.
WARNfNG -
When reinstalling
a
used air filter element. reinstall
the filter in the same position that it was in be/ore re-
moval. Reversed installation will allow accumulated
dirt to be drawn into the engine.
Spark plugs, replacing
High temperature and high-voltage sparks eventually wear
out the spark plug electrodes , and the spark plug s must be re-
placed.
On M20 and M30 engines. gently remove the spark plug
wire by pulling on the protective boot. Blow or brush away any
dirt from around the base of the plug to prevent it from entering
the engine when the plug is removed.
On M50 and M60 engines, individual ignition coils are
mounted above each spark plug. To access the plugs. the ig-
nition coils must first be removed as described in 120 Ignition
System-DME.
CAUTlON-
Spark ptugs should be repla ced one at
a
time
so
that the spark plug wires do not get mixed up. II all
of the wires need to be removed together, label
each wire so that they can be reinstalled on the
correct spark plug.
Use a 13/16 in. or 518 in. spark plug socket to remove spark
plugs . The correct spark plugs for the different engines cov-
ered by this manual are listed in Table i. Use a spark plug gap
gauge to check the gap. if applicable. If necessary. bend the
outer electrode slightly to adjust the gap to meet the specifica-
tion. Do not bend or file the center electrode.